Levomilnacipran, (1S,2R)-cis-2-(aminomethyl)-N,N-diethyl-1-phenylcyclopropanecarboxamide (also defined (1S,2R)-cis-milnacipran) is a drug actually used in depressive disorders and fibromyalgia, and has the following formula (I)

Levomilnacipran is commonly used in the therapy in form of hydrochloride salt. Several synthesis of levomilnacipran are known, most of which consider the resolution of racemic cis-milnacipran by means of resolving agents such as, e.g., optically active derivatives of tartaric acid and mandelic acid.
Such processes, in addition to not providing the desired compound with good yields and acceptable purity, have the disadvantage of a difficult recovery of the resolving agent from the reaction mother liquors; such difficulty represents a problem from the industrial point of view since it is clear that, in the economy of a large scale synthesis, the simple and quantitative recovery of all re-usable reaction agents is fundamental.